This invention relates to devices for protecting electronic equipment against electro static discharge (ESD).
A memory card is often used in different electronic equipment having a control unit. A memory card is a bearer of information that is readable by the control unit in said electronic equipment. A user can change the features of electronic equipment by changing the memory card to a new one containing different information. In portable transceivers, like mobile stations for mobile radio telecommunication, a memory card is used that contains subscriber and operator information. This card is called a SIM chip card (Subscriber Identification Module). An interface providing electrical connections between a SIM chip card and electronics internal to the portable transceiver is called a SIM chip card reader. Once the SIM chip card is retained in the reader, sliding contacts of the reader are coupled to the SIM chip card contacts, allowing the portable transceiver access to the information stored within the SIM chip card. The electrical operation of the SIM chip card is described in International Standards Organisation (ISO) Document #7816-3: 1988 (E), Technical Committee ISO/TC 97, Information Processing Systems, May 15, 1988 (First Edition).
Developments have resulted in smaller electronic components and circuits internal to the portable transceiver that is working at lower and lower drive voltages. Said electronics and circuits become therefore more sensitive to ESD charges that could rise to many thousands of volts. The contacts of the reader could conduct said high charges to said electronics causing a lot of damage inside the transceiver.
One object of this invention is to provide a design that solves the problem to protect electronic equipment having a memory card receptacle against ESD damage.
This object is achieved by providing said memory card receptacle with at least one grounding contact member.
A more detailed description of the invention is that the memory card receptacle has at least one grounding contact member, whereat each contact of the memory card receptacle is in contact with a grounding contact member when there is no memory card inserted into the device.
The advantage is that any static discharge electric charges will have a controlled discharge path and the components of an electronic equipment device will be protected against expensive damages caused by high ESD charges.
The invention will now be described in more detail with reference to the enclosed drawings.